HIV positive patients who have secondary infections (tuberculosis, fungal or bacterial) will be randomly assigned to treatment with either recombinant human growth hormone, thalidomide, or placebo for a 4-week period concurrent with initiation of standard treatment for their specific infection. The study will test the hypothesis that such therapies can mitigate weight loss and specifically the loss of lean body mass in such individuals and that any salutary effects will be mediated through effects on different components of the energy balance equation. Individuals will be studied on either an inpatient or outpatient basis in the GCRC and undergo measurements of body composition, energy balance, leucine flux and extensive monitoring of safety.